Fluid spray nozzles are used for many purposes to dispense various fluids such as water, paint, chemical insecticides, pesticides and various emulsions and foams on a variety of applied media. One example of spray nozzle utilization is for cleaning dirty or soiled equipment, a specific example of which is a coin-operated car wash. Typically such a car wash provides a source of liquid cleaning agent, e.g. a chemical detergent mixed with water, and an apparatus for applying the cleaning agent. This may be a fluid supplied brush which is used to create a cleaning foam, but more recently foam generating nozzles have been developed for spraying the cleaning agent directly on the parts to be cleaned. Generally these foaming nozzles operate at relatively low pressure on the order of about 30-45 psi to prevent excessive splashing and wasteful usage of the cleaning agent. Two examples of such foaming spray nozzles are illustrated in U.S. Pat. No. 3,784,111 assigned to the same assignee as the present application.
Once the foamed cleaning agent is applied and allowed to work for a brief period of time, it is then rinsed from the apparatus being cleaned. Rinsing is usually done with plain tap water and is sprayed at relatively high pressure, e.g. on the order of 500 psi or more to literally scrub the surface clean and carry the loosened dirt away. It will be appreciated that most spray cleaning operations require separate foaming nozzles and low pressure sources of cleaning agents and separate high pressure rinse nozzles which literally doubles the equipment requirements for such installations. In other instances, a separate compressed air source is provided for use with the spray nozzle which is then operated at low pressure so that the air is injected to generate a foam of the cleaning solution. However, this too requires a relatively expensive air supply arrangement and atomizing nozzle adaptation.
Accordingly, it is the primary aim of the present invention to provide a dual purpose foam generating and high pressure rinse nozzle. A more specific object is to provide such a nozzle which automatically operates to efficiently produce a well mixed dense foam when supplied with a low pressure foaming solution and which is also capable of automatically discharging a high pressure jet spray in a selected spray pattern when supplied with a high pressure fluid such as rinse water.
Another object of the invention is to provide a dual purpose nozzle of the above type which is relatively simple and economical to manufacture and easy to operate, clean and service, when necessary. It is likewise an object to provide such a nozzle which is durable and thus gives long lasting and trouble free service.